Study estimates human information capacity at 256 exabytes

How much information could you store on every
technological device in the world? Every hard drive, book, video
tape and microchip on a credit card? A research team from the University of Southern
California has estimated that figure, in 2007, to have been 256
exabytes of data.

That's a 256 billion gigabytes, the equivalent of 1.2
billion average PC hard drives, enough CDs to make a stack which would reach
beyond the moon and 15 libraries for every person on the
planet.

As for broadcasting information, like TV and GPS, humankind
sent approximately 1.9 zettabytes of information in 2007. In that
same year, we shared 65 exabytes of data through two-way
communications, like phones. In terms of computing, the world's
general-purpose computers performed 6.4 x 10^18 instructions per
second. If you did all that by hand, it would take 2,200 times the
period since the Big Bang.

To come up with these staggering numbers, study author
Martin Hilbert and his team at the University of Southern
California estimated the amount of data held on 60 different
digital and analogue technologies -- including x-ray films and
floppy disks -- from 1986 to 2007. They then used this data to look
at trends and growth rates.

For example, 2002 was the year digital storage capacity
overtook the world's total analogue capacity. By 2007, almost 94 percent of the world's
data was stored in a digital format.

The team also saw computing power grow by 58 percent a year
-- ten times faster than the gross domestic product of the United
States -- and telecommunications and storage capacity grew 28 percent and 23
percent annually respectively.

However, as impressive as those numbers are, they're dwarfed
by the information processing and storage seen in nature. That
mammoth 295 exabyte figure is less than 1 percent of the
information stored in all the DNA molecules of a single human being.

The number of calculations performed by the world's
computers? A human brain could do that, by itself. And it would be
impossible, says Hilbert, to write down the names of every star in
the known universe, even if you had access to every storage medium
on the planet.

If, duly humbled, you want to see the research, it was published in the 10 February issue of the journal
Science.

Edited by Duncan Geere

Comments

I don't think that you can measure human brain capacity in terms of computer capacity, surely the brain operates completely differently to a hard drive, for all we know it could be storing memories we remember as a text document!I understand where this is coming from thought, if a computer had to store what we remember, it would need 256 exabytes of storage. But I don't think that you can say that the Human Brain has 256 exabytes of storage. Or maybe you can.

Adam

Feb 14th 2011

A brain the size of a "car park" and the Planet as the Hard-drive .... my wife reckons she has total recall and there is no limit to her data base just Serious selectivity in what she deems worthy of capture .... Mmmmm !